With the increasing sophistication and complexity of control systems using clusters of modules interconnected by a common network or backplane it becomes increasingly necessary to have high bandwidth connections between the modules. Most of the current common networks use an electrical backplane to provide electrical transmission between modules through a gang of mechanical pin type connectors. In order to provide higher bandwidth transmission between modules it is preferred to use an optical backplane because the optical backplane provides higher transmission rates, has greater noise immunity, and is not limited by the number of modules or the length of the physical path between modules. In order to provide the benefits of both an electrical backplane and an optical backplane the optical backplane has been formed as an integral part of the electrical backplane so that integral backplane can be connected or disconnected as a unit.
The present invention provides an improved common network that allows one to have the benefits of both optical backplanes and electrical backplanes without having to connect or disconnect both the electrical backplane and the optical backplane as an integral unit. The present invention provides a removable and separable optical backplane that has optical connectors that can be inserted through openings in the electrical backplane and into optical engagement with the electronic system modules. Thus the invention permits the optical backplane to be connected directly to the system modules when the electrical backplane is connected to the system modules and allows the optical backplane to be disconnected from the system modules and removed from the electrical backplane without having to either disconnect or reconnect the electrical backplane. By permitting one to have an optical backplane that is free of the electrical backplane it allows one to physically remove the optical backplane from the electrical backplane which permits easy repair and maintenance as well as more flexibility in design of the system.